Round 1 Screening : Design Key Generation Service.
Round 2 Screening : Return max nodes on one single level of binary tree.

Round 1: https://www.***.org/count-all-k-sum-paths-in-a-binary-tree/
Round 2: course schedule 2
Round 3: Tiny url, req gathering, estimation and design HLD
Round 4: 3 LP questions, news aggregator HLD
Round 5: 4 LP and bit of project discussion.